feat: ignore underscores in input

this isn't useful for typst usually,
since underscores are subscript and don't appear in expressions much.

however, when using tylc as a standalone calculator,
this is useful eg to seperate sets of three digits.

idea totally stolen from rust literals

note that this might cause problems when it comes to special variables,
eg A_n for Avogadro's number (but just A is fine)

src/formatting.rs

@@ -2,7 +2,9 @@ use rug::Float;
 
 use crate::nodes::{self, Error};
 
-pub fn pretty_eval(mut input: String, max_digits: usize) -> Result<String, Error> {
+pub fn pretty_eval(input: &str, max_digits: usize) -> Result<String, Error> {
+    let mut input = input.replace('_', "");
+
     // no need to remove the characters here,
     // as we ignore the them in all other logic already
     let should_add_back_alignment = input.contains('&');
@@ -49,20 +51,20 @@ pub fn pretty_eval(mut input: String, max_digits: usize) -> Result<String, Error
 }
 #[test]
 fn test_character_readdition() {
-    assert_eq!(pretty_eval(" = 11".into(), 10).unwrap(), " = 11");
-    assert_eq!(pretty_eval(" &= 11".into(), 10).unwrap(), " & = 11");
-    assert_eq!(pretty_eval(" & 11".into(), 10).unwrap(), " & 11");
-    assert_eq!(pretty_eval(" & 11 \\".into(), 10).unwrap(), " & 11 \\");
+    assert_eq!(pretty_eval(" = 11", 10).unwrap(), " = 11");
+    assert_eq!(pretty_eval(" &= 11", 10).unwrap(), " & = 11");
+    assert_eq!(pretty_eval(" & 11", 10).unwrap(), " & 11");
+    assert_eq!(pretty_eval(" & 11 \\", 10).unwrap(), " & 11 \\");
 }
 #[test]
 fn test_basic_up_to_999() {
-    assert_eq!(pretty_eval("1".into(), 10).unwrap(), "1");
-    assert_eq!(pretty_eval("10".into(), 10).unwrap(), "10");
-    assert_eq!(pretty_eval("100".into(), 10).unwrap(), "100");
-    assert_eq!(pretty_eval("999".into(), 10).unwrap(), "999");
-    assert_eq!(pretty_eval("1000".into(), 10).unwrap(), "1 * 10^3");
+    assert_eq!(pretty_eval("1", 10).unwrap(), "1");
+    assert_eq!(pretty_eval("10", 10).unwrap(), "10");
+    assert_eq!(pretty_eval("100", 10).unwrap(), "100");
+    assert_eq!(pretty_eval("999", 10).unwrap(), "999");
+    assert_eq!(pretty_eval("1000", 10).unwrap(), "1 * 10^3");
 
-    assert_eq!(pretty_eval("11.111111".into(), 10).unwrap(), "11.111111");
+    assert_eq!(pretty_eval("11.111111", 10).unwrap(), "11.111111");
 }
 
 pub fn get_significant_digits(n: &Float) -> usize {

src/main.rs

@@ -17,7 +17,7 @@ fn main() -> ExitCode {
             buf
         });
 
-    match lib::formatting::pretty_eval(input, 10) {
+    match lib::formatting::pretty_eval(&input, 10) {
         Ok(s) => println!("{s}"),
 
         Err(e) => {